Known in the art are various processes for the production of unsaturated hydrocarbons.
Thus, known is a process for the production of unsaturated hydrocarbons from saturated ones at a temperature within the range of from 400.degree. to 800.degree. C. in the presence of gaseous oxygen and a catalyst containing molybdenum as well as nickel or cobalt. The yield of butadiene produced by this process does not exceed 10.1% with the selectivity relative thereto of 31.0% and relative to the total butylenes-butadiene of 46.4%.
Also known in the art is a process for producing mono- and di-olefins by an oxidizing dehydrogenation of paraffins at a temperature within the range of from 400.degree. to 700.degree. C. in the presence of gaseous oxygen and a catalyst consisting of oxides of molybdenum and/or tungsten and at least one of the following metals: chromium, manganese, iron, nickel and cadmium. In accordance with this process, the yield of butadiene from n-butane does not exceed 21.6% with a selectivity relative thereto of 53.6% and relative to the total butylenes-butadiene of 64.8%.
A principal disadvantage of the above-discussed prior art processes resides in low conversion of dehydrogenated hydrocarbons and insufficient selectivity relative to the desired products.
The closest analogue of the process according to the present invention is a process for producing mono- and diolefins by an oxidizing dehydrogenation of, e.g. paraffin hydrocarbons, at a temperature within the range of from 400.degree. to 700.degree. C. and the molar ratio of oxygen to the paraffin hydrocarbon of from 0.1 to 3.0:1 in the presence of an inert vehicle such as argon, nitrogen, helium, steam or mixtures thereof.
The process is conducted on a catalyst comprising oxides of, e.g., molybdenum and magnesium, with additives of cobalt, iron, chromium, vanadium, nickel, silicon, tin, boron, bismuth, titanium, niobium, gadolinium, dysprosium, gallium and zirconium. The yield of butadiene from n-butane by this process is 36.6% with a selectivity relative thereto of 54.7% and relative to the total butylenes-butadiene of 64.3%.
For increasing the mechanical strength of the catalyst, the active component is applied on a carrier, such as alumosilicate, aluminum oxide, silica gel. However, the use of such catalysts, e.g. with the application of alumosilicate, in accordance with the above-cited method, leads to lowering of the butadiene yield from n-butane to 4.7% with the selectivity reduced to 14.3%. Thus, the method is characterized by low selectivity, and, in the case of using a catalyst with a carrier, by a low yield of the desired dehydrogenation products.